Short-Term Fix for Dreamliner’s Battery Problem Expected Soon

A diagram, from Boeing, explaining the electrical systems of the 787 Dreamliner, which has been grounded after the batteries in two planes experienced thermal runaway. Image: Boeing

Boeing continues defending the lithium-ion batteries that have grounded the world’s fleet of 787 Dreamliner airliners, arguing the technology behind the “game changing” airplane remains the best choice for an aircraft so heavily dependent upon electricity.

The company’s continued justification of the batteries — two of which have experienced “thermal runaway” that prompted one to catch fire and the other to begin smoking as it melted — came as it is said to be developing a reinforced battery box which it hopes will get those 50 Dreamliners back in service.

The company’s flagship airliner has been grounded for more than five weeks since a pair of Dreamliners experienced thermal runaway that destroyed the batteries. The National Transportation Safety Board believes one of the events, a fire aboard a 787 in Boston, started with a short-circuit within a single cell inside the 63-pound battery. It is expected to release a preliminary report within weeks. But even if that report identifies a “root cause” for the problem, it’s widely assumed that it will take months to design, build and test a permanent fix and install it in the planes currently sitting idle around the world.

In an effort to get those 787s flying sooner, Boeing is expected to propose a short-term fix for the battery problem as early as this week, according to The Seattle Times. It is expected to focus on a heavy-duty containment box to replace the relatively simple box now used to hold the lithium-ion cells in each of two electrical bays in the airplane. Those electrical bays are designed to handle a potential fire and protect vital systems from damage. The Federal Aviation Administration and the NTSB have made it clear a better system is needed after the two battery failures, noting that such an event was expected to happen once in every ten million flight hours.

Boeing began limited flight testing last week in an effort to gather more data about the batteries and electrical system. Building a stronger containment box out of titanium or steel could completely contain any thermal damage or fire, protecting surrounding systems in the event of a fire. The box would vent smoke directly outside the aircraft. Boeing may be able to show that another battery fire would pose no threat to the aircraft or passengers.

Even as it scrambles to determine what’s gone wrong, Boeing remains steadfast in its choice of lithium-ion batteries. It posted a trove of documents and diagrams explaining the technology and its benefits. It amounts to a “Aircraft Electricity 101″ primer outlining the composite airliner’s pioneering use of electricity to power systems that traditionally use hydraulic power. Much of what Boeing released this week highlights the “more electric” airplane design and the benefits for airlines. There is nothing outlining what may have caused the thermal runaway incidents.

The company also posted a 30-minute video of Mike Sinnett, Boeing’s vice president of engineering, explaining the world’s most electric airliner. The video appears to be internally produced to answer many of the questions being raised about the 787, and was not an event attended by media.

“There’s been a lot of interest in what an electrical power system is on an airplane,” Sinnett begins the primer, with a friendly tone that makes it sound like all is well in Boeing’s engineering department. The video is a bit like a basic engineering course — you need a previous interest in the topic to stick around through to the third act — but it does a good job of explaining the electrical systems of the 787.

For all of Boeing’s defense, its problems were enough to prompt Airbus to announce last week that it is ditching plans to use lithium-ion batteries and will instead use tried-and-true nickel-cadmium batteries in its newest jet, the A350 XWB. The A350 XB doesn’t rely so heavily on electricity to power various systems, using instead more traditional hydraulic power.

As if this weren’t enough, Boeing faces a potential strike by the Society of Professional Engineering Employees in Aerospace. The union is recommending that members reject the most recent contract offer, citing pension issues. The 23,000 employees represented by SPEEA voted on the contract Tuesday.

A strike could lead to a shutdown of assembly lines in Everett, Washington that manufacture the 747, 767, 777 and 787 airliners and at a factory in nearby Renton that builds the 737. There is a second 787 assembly line in South Carolina, but the unions do not represent employees there.

Update: Boeing engineers represented by SPEEA accepted the contract offer, avoiding a potential strike. However a smaller group of technical workers represented by SPEEA rejected their contract, authorizing a strike. The technical workers are expected to return to negotiations with Boeing.

The 787 Dreamliner’s battery, explained. Image: Boeing
Boeing Explains The Dreamliner's Lithium-Ion Electrical System
Mike Sinnett, Boeing's vice president and chief project engineer for the 787 Dreamliner program, explains the lithium-ion battery system that has grounded the world's fleet of 787s after two planes experienced battery fires.